Closure for switch housings



y 1942- H.W. BATCHELLER' I 2,289,863

CLOSURE Fox swr'rcu Hous'mGs Filed Aug. 30, 1 938 Patented July 14, 1942 CLOSURE FOR SWITCH HOUSINGS Hugh W. Batoheller, Newton, Mass, assignor to Standard Mfg. 00., Worcester, Mass, at corporation of Massachusetts Application August 30, 1938, Serial No. 227,4ii

1 Claim. (Cl. 292-19) This invention relates to a closure means for a housing, and more particularly to means for detachably securing to the housing shell for an electric switch a back plate which completes the enclosure of the switch elements. switches of the type adapted to be mounted on the dashboard of an automobile, for convenience in controlling lights, heater units and other accessories, often include a housing comprising a metal shell and a back plate attached to the shell. The back plate is usually of insulating material such as porcelain, Bakelite, vulcanized fiber or the like, so that the terminals of the switch can be economically mounted directly thereon. Tongues or cars have been provided on the metal shells to be bent behind the back plates so as to hold the shell and plate in assembled relation. In assembling such a shell with a back plate of frangible material, however, a considerable percentage of breakage has resulted. Moreover, assembled housings which have been opened for inspection or adjustment of the switch elements therein have been difficult to reassemble satisfactorily.

According to the present invention, I provide closure means which are not only efficient inholding the shell and back plate together when assembled, but which also facilitate the operation of assembling the parts of the housing and make it possible to open the housing quickly and easily and to secure the back plate in place again.

According to the present invention, a bail or clip of spring wire bears against the rear face of the back plate and has its ends caught in apertures in the sides of the metal shell. The bail has portions standing away from the back plate to provide yielding elements which permit the ends of the bail to be sprung into and out of the apertures.

For a more complete understanding of the invention, reference may be had to the following description thereof, and to the drawing in which Figure l is a side elevation of a switch embodying the invention.

Figure 2 is a rear elevation of the same.

Figure 3 is an elevational view of the bail or fastening element.

Figure 4 is a sectional view, on a larger scale, on the line 44 of Figure 1.

Figure 5 is a side elevation of a modified form of the invention.

Figure 1 illustrates an electric switch of the push and pull type, the switch elements being contained in a housing which consists of a cupshaped metal shell l0 having an open end nor- Small .jecting neck mally closed by a back plate E2 of substantial thickness, with a rabbet groove about its periphery which receives the rim of the shell ll] flush with the edge surface of the plate, as shown in Figure 4. The housing also has a forwardly prol 'i which is preferably screwthreaded to receive a pair of nuts I5 by which the switch may be conveniently mounted on a supporting wall such as the dashboard of an automobile, the neck M projecting through a suitable aperture in the wall. The back plate I2 is preferably of insulating material, such as porcelain, Bakelite, vulcanized fiber or the like. Extending through this plate are a pair of conductors having terminals 20 at the outside surface of the plate. These conductors have suitable contact elements (not shown) at the inner surface of the plate for engagement by a movable switch elernent or bridging conductor 22 to close or open the switch. The element 2'2 is snapped into or out of engagement with said contact elements by a cam member 24 mounted. on a stem which projects through the neck l4 and terminates in a suitable handle 26. The structure and operation of the switch itself is, however, no part of this invention.

Housings for switches of this type and of other types for similar purposes often consist of a metal shell somewhat similar to the shell [0 and a back plate of insulating material somewhat similar to the back plate 12. It is customary to provide a series of tongues or ears on the rear edge of the metal shell, these tongues being bent to engage the rear face of the plate so as to hold the shell and plate in assembled relation. Where a frangible material such as porcelain is employed in the back plate, the operation of bending the ears against the back of the plate results in a considerable loss by breakage of the plates. Furthermore, these tongues must be straightened out to open the housing for access to the parts of the switch. After the tongues have been thus straightened, it is difficult to bend them back properly to secure the housing in its assembled condition, and repeated bending of the tongues soon results in the breaking off of one or more of them. According to the present invention, fastening means are provided which are simple in structure, which are easily applied in assembling of the switch and housing, which satisfactorily secure the housing in assembled condition, and which are easily removed and replaced any number of times without injury to the housing, the back plate or the securing means. To this end, I employ a fastening element consisting of a single piece of spring wire bent preferably to the shape illustrated in Figure 3, this being approximately a U-shaped with an intermediate portion 30, a pair of parallel arms 32 and a pair of alined catches 34. The catches 34 are the end portions of the arms 32 and are bent so as to project toward each other as indicated. The central part 36 of the intermediate portion 30 is adapted to bear against the rear face of the plate I2, the plate being preferably provided With a transverse channel or groove 40 to receive the intermediate portion 30 of the fastening element. This intermediate portion has, in addition to its central part 36, end parts 38 which are bent or offset away from the catches 34 so that they are free from contact with the back plate. These bowed parts of the fastening element are thus between the central part 36 of the fastening element and the arms 32 so that they form yielding spring elements which can be sufficiently sprung when the part 36 is engaged in the channel 40 to permit the catches 34 to enter a pair of small holes 42 in opposite sides of the shell H3. These catches 34 then engage the edges of their respective holes 42 and are held tightly in engagement with such edges by the spring elements 38, so that the back plate I2 is maintained firmly in position against the open end of the housing shell in.

The fastening element can readily be removed so as to open the housing and obtain access to the switch parts therein by springing the catches 34 free from the holes 42. This can be done an indefinite number of times without injury to any part of the housing or to the fastening means itself,

4 In order to facilitate the assembling of the housing and fastening element therefor without the use of any tool, the shell I0 may be provided with an inclined slot 44 communicating with each of the holes 42. In assembling the housing, the catches 34 are easily introduced into the ends of the slots 44 remote from the holes 42, such ends being nearer to the channel 43 than are the holes themselves. The arms 32' of the fastening element are then pressed by the fingers of the operator so as to cause the catches 34 to ride on the inclined edges of the slots 44 as cam surfaces until the catches 34 snap into the respective holes 42.

It is evident that various modifications and changes may be made in the particular embodiments of the invention herein shown and described without departing from the spirit or scope thereof as defined in the following claim.

I claim:

A housing for an electric switch, comprising a cup-shaped metal shell having a pair of holes at opposite points in the side wall thereof, a back plate of substantial thickness fitted across the opening of the shell cup, said plate having around its periphery a rabbet groove in which the rim of the shell cup is fitted flush with the edge surface of the plate, said plate also having in its outer face a transverse groove parallel to a line between said holes, and a piece of spring wire having a midportion disposed in said transverse groove, the end parts of said mid-portion being bent away from the bottom of said groove to form spring elements, said wire having parallel portions disposed against the surface of the back plate and shell between the ends of said groove and said holes and terminating in short hook portions projecting through said holes.

HUGH W. BATCHELLER. 

